The present invention relates in general to a coaxial rotary joint. In accordance with the invention there is disclosed herein an electric coaxial rotary connector having relatively rotatable male and female housings defining an outer conductor and including means also defining an inner conductor. In the embodiment described hereinafter the invention is taught in connection with the known type N coaxial connector. However, it is understood that the principles of the invention may be applied to any types of connectors, even those carrying only a single conductor.
The present coaxial rotary joint is a relatively complex device requiring inner and outer spring finger contacts and separate biasing springs for the contacts associated with one of the housings forming the connector. There are several components in the prior art joint that make the construction quite expensive. The spring finger contacts require a separate slotting operation and heat treating during manufacture thus making for a much more expensive part in comparison to a standard screw machine part. Also, in order to provide enough area for spring contact and proper finger contact operation, the contacts which may be silver-graphite contacts have to be relatively large. Because these contacts are quite expensive, this also increases the cost of the overall device. The other contacts may be coin silver contacts. These contacts are also expensive but in the existing designs are required due to contact noise requirements. Also, in existing devices, leaf-type contacts are required to allow some compliance at the contact interface with the silver-graphite contact to control contact pressure in the event of wear and temperature variations.
Accordingly, one object of the present invention is to provide an improved rotary electrical connector, preferably a coaxial rotary joint that is of improved design in comparison with existing connectors of that type.
Another object of the present invention is to provide an improved rotary electrical connector that is of simplified construction, that does not require any unusual fabrication techniques, and that can be manufactured relatively inexpensively.
A further object of the present invention is to provide an improved rotary electrical connector that, albeit of simplified construction, has excellent contact noise parameters.